Patents by Inventor Lars Villemoes

Lars Villemoes has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20210035592
    Abstract: In some embodiments, a pitch filter for filtering a preliminary audio signal generated from an audio bitstream is disclosed. The pitch filter has an operating mode selected from one of either: (i) an active mode where the preliminary audio signal is filtered using filtering information to obtain a filtered audio signal, and (ii) an inactive mode where the pitch filter is disabled. The preliminary audio signal is generated in an audio encoder or audio decoder having a coding mode selected from at least two distinct coding modes, and the pitch filter is capable of being selectively operated in either the active mode or the inactive mode while operating in the coding mode based on control information.
    Type: Application
    Filed: October 16, 2020
    Publication date: February 4, 2021
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Barbara RESCH, Kristofer KJÖRLING, Lars VILLEMOES
  • Publication number: 20210012781
    Abstract: Exemplary embodiments provide encoding and decoding methods, and associated encoders and decoders, for encoding and decoding of an audio scene which is represented by one or more audio signals. The encoder generates a bit stream which comprises downmix signals and side information which includes individual matrix elements of a reconstruction matrix which enables reconstruction of the one or more audio signals in the decoder.
    Type: Application
    Filed: July 24, 2020
    Publication date: January 14, 2021
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Heiko PURNHAGEN, Lars VILLEMOES, Leif Jonas SAMUELSSON, Toni HIRVONEN
  • Publication number: 20200411019
    Abstract: A method for decoding an encoded audio bitstream is disclosed. The method includes receiving the encoded audio bitstream and decoding the audio data to generate a decoded lowband audio signal. The method further includes extracting high frequency reconstruction metadata and filtering the decoded lowband audio signal with an analysis filterbank to generate a filtered lowband audio signal. The method also includes extracting a flag indicating whether either spectral translation or harmonic transposition is to be performed on the audio data and regenerating a highband portion of the audio signal using the filtered lowband audio signal and the high frequency reconstruction metadata in accordance with the flag.
    Type: Application
    Filed: January 28, 2019
    Publication date: December 31, 2020
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Kristofer KJOERLING, Lars VILLEMOES, Heiko PURNHAGEN, Per EKSTRAND
  • Publication number: 20200411024
    Abstract: Embodiments relate to an audio processing unit that includes a buffer, bitstream payload deformatter, and a decoding subsystem. The buffer stores at least one block of an encoded audio bitstream. The block includes a fill element that begins with an identifier followed by fill data. The fill data includes at least one flag identifying whether enhanced spectral band replication (eSBR) processing is to be performed on audio content of the block. A corresponding method for decoding an encoded audio bitstream is also provided.
    Type: Application
    Filed: July 17, 2020
    Publication date: December 31, 2020
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Publication number: 20200395023
    Abstract: The invention provides methods and devices for outputting a stereo audio signal having a left channel and a right channel. The apparatus includes a demultiplexer, decoder, and upmixer. The upmixer is configured operate either in a prediction mode or a non-prediction mode based on a parameter encoded in the audio bitstream.
    Type: Application
    Filed: July 16, 2020
    Publication date: December 17, 2020
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Heiko Purnhagen, Pontus Carlsson, Lars Villemoes
  • Publication number: 20200395025
    Abstract: The invention provides an efficient implementation of cross-product enhanced high-frequency reconstruction (HFR), wherein a new component at frequency Q?+r?0 is generated on the basis of existing components at ? and ?+?0. The invention provides a block-based harmonic transposition, wherein a time block of complex subband samples is processed with a common phase modification. Superposition of several modified samples has the net effect of limiting undesirable intermodulation products, thereby enabling a coarser frequency resolution and/or lower degree of oversampling to be used. In one embodiment, the invention further includes a window function suitable for use with block-based cross-product enhanced HFR. A hardware embodiment of the invention may include an analysis filter bank, a subband processing unit configurable by control data and a synthesis filter bank.
    Type: Application
    Filed: June 30, 2020
    Publication date: December 17, 2020
    Applicant: Dolby International AB
    Inventor: Lars Villemoes
  • Publication number: 20200388300
    Abstract: The present document relates to audio source coding systems which make use of a harmonic transposition method for high frequency reconstruction (HFR), as well as to digital effect processors, e.g. exciters, where generation of harmonic distortion add brightness to the processed signal, and to time stretchers where a signal duration is prolonged with maintained spectral content. A system and method configured to generate a time stretched and/or frequency transposed signal from an input signal is described. The system comprises an analysis filterbank configured to provide an analysis subband signal from the input signal; wherein the analysis subband signal comprises a plurality of complex valued analysis samples, each having a phase and a magnitude. Furthermore, the system comprises a subband processing unit configured to determine a synthesis subband signal from the analysis subband signal using a subband transposition factor Q and a subband stretch factor S.
    Type: Application
    Filed: June 23, 2020
    Publication date: December 10, 2020
    Applicant: Dolby International AB
    Inventor: Lars VILLEMOES
  • Patent number: 10863299
    Abstract: A multi-channel decoder for generating a binaural signal from a downmix signal using upmix rule information on an energy-error introducing upmix rule for calculating a gain factor based on the upmix rule information and characteristics of head related transfer function based filters corresponding to upmix channels. The one or more gain factors are used by a filter processor for filtering the downmix signal so that an energy corrected binaural signal having a left binaural channel and a right binaural channel is obtained.
    Type: Grant
    Filed: September 25, 2019
    Date of Patent: December 8, 2020
    Assignee: Dolby International AB
    Inventor: Lars Villemoes
  • Publication number: 20200380999
    Abstract: The present invention proposes a new method for improving the performance of a real-valued filterbank based spectral envelope adjuster. By adaptively locking the gain values for adjacent channels dependent on the sign of the channels, as defined in the application, reduced aliasing is achieved. Furthermore, the grouping of the channels during gain-calculation, gives an improved energy estimate of the real valued subband signals in the filterbank.
    Type: Application
    Filed: June 14, 2020
    Publication date: December 3, 2020
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Kristofer KJOERLING, Lars VILLEMOES
  • Publication number: 20200349911
    Abstract: The present document relates to audio coding systems which make use of a harmonic transposition method for high frequency reconstruction (HFR), and to digital effect processors, e.g. so-called exciters, where generation of harmonic distortion adds brightness to the processed signal. In particular, a system configured to generate a high frequency component of a signal from a low frequency component of the signal is described. The system may comprise an analysis filter bank (501) configured to provide a set of analysis subband signals from the low frequency component of the signal; wherein the set of analysis subband signals comprises at least two analysis subband signals; wherein the analysis filter bank (501) has a frequency resolution of ?f.
    Type: Application
    Filed: May 18, 2020
    Publication date: November 5, 2020
    Applicant: Dolby International AB
    Inventors: Per EKSTRAND, Lars VILLEMOES, Per HEDELIN
  • Patent number: 10818306
    Abstract: A method for decoding an encoded audio bitstream is disclosed. The method includes receiving the encoded audio bitstream and decoding the audio data to generate a decoded lowband audio signal. The method further includes extracting high frequency reconstruction metadata and filtering the decoded lowband audio signal with an analysis filterbank to generate a filtered lowband audio signal. The method also includes extracting a flag indicating whether either spectral translation or harmonic transposition is to be performed on the audio data and regenerating a highband portion of the audio signal using the filtered lowband audio signal and the high frequency reconstruction metadata in accordance with the flag.
    Type: Grant
    Filed: March 19, 2018
    Date of Patent: October 27, 2020
    Assignee: Dolby International AB
    Inventors: Lars Villemoes, Heiko Purnhagen, Per Ekstrand
  • Patent number: 10811024
    Abstract: In some embodiments, a pitch filter for filtering a preliminary audio signal generated from an audio bitstream is disclosed. The pitch filter has an operating mode selected from one of either: (i) an active mode where the preliminary audio signal is filtered using filtering information to obtain a filtered audio signal, and (ii) an inactive mode where the pitch filter is disabled. The preliminary audio signal is generated in an audio encoder or audio decoder having a coding mode selected from at least two distinct coding modes, and the pitch filter is capable of being selectively operated in either the active mode or the inactive mode while operating in the coding mode based on control information.
    Type: Grant
    Filed: March 12, 2019
    Date of Patent: October 20, 2020
    Assignee: Dolby International AB
    Inventors: Barbara Resch, Kristofer Kjörling, Lars Villemoes
  • Publication number: 20200304913
    Abstract: A method and apparatus for reconstructing N audio channels from M audio channels is disclosed. The method includes receiving a bitstream containing an encoded audio signal representing the M audio channels and decoding the encoded audio signal to obtain a frequency domain representation of the M audio channels. The method further includes extracting a parameter from the bitstream and reconstructing at least one of the N audio channels using the parameter. The parameter represents an angle between two signals, at least one of which is included in the M audio channels.
    Type: Application
    Filed: April 13, 2020
    Publication date: September 24, 2020
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Heiko PURNHAGEN, Lars VILLEMOES, Jonas ENGDEGARD, Jonas ROEDEN, Kristofer KJOERLING
  • Publication number: 20200302943
    Abstract: An encoding system encodes an N-channel audio signal (X), wherein N?3, as a single-channel downmix signal (Y) together with dry and wet upmix parameters ({tilde over (C)}, {tilde over (P)}). In a decoding system, a decorrelating section outputs, based on the downmix signal, an (N?1)-channel decorrelated signal (Z); a dry upmix section maps the downmix signal linearly in accordance with dry upmix coefficients (C) determined based on the dry upmix parameters; a wet upmix section populates an intermediate matrix based on the wet upmix parameters and knowing that the intermediate matrix belongs to a predefined matrix class, obtains wet upmix coefficients (P) by multiplying the intermediate matrix by a predefined matrix, and maps the decorrelated signal linearly in accordance with the wet upmix coefficients; and a combining section combines outputs from the upmix sections to obtain a reconstructed signal ({circumflex over (X)}) corresponding to the signal to be reconstructed.
    Type: Application
    Filed: April 7, 2020
    Publication date: September 24, 2020
    Applicant: DOLBY INTERNATIONAL AB
    Inventors: Lars VILLEMOES, Heidi-Maria LEHTONEN, Heiko PURNHAGEN, Toni HIRVONEN
  • Publication number: 20200294516
    Abstract: The present invention relates to transposing signals in time and/or frequency and in particular to coding of audio signals. More particular, the present invention relates to high frequency reconstruction (HFR) methods including a frequency domain harmonic transposer. A method and system for generating a transposed output signal from an input signal using a transposition factor T is described. The system comprises an analysis window of length La, extracting a frame of the input signal, and an analysis transformation unit of order M transforming the samples into M complex coefficients. M is a function of the transposition factor T. The system further comprises a nonlinear processing unit altering the phase of the complex coefficients by using the transposition factor T, a synthesis transformation unit of order M transforming the altered coefficients into M altered samples, and a synthesis window of length Ls, generating a frame of the output signal.
    Type: Application
    Filed: March 23, 2020
    Publication date: September 17, 2020
    Applicant: Dolby International AB
    Inventors: Per EKSTRAND, Lars VILLEMOES
  • Patent number: 10770082
    Abstract: There is provided an audio decoder and a method therein for transforming a digital audio signal from a first frequency domain to a second frequency domain. For each received frame of the digital audio signal, the method identifies an upper limit of the frequency range, and if the upper limit of the frequency range is below the Nyquist frequency of said frame of the digital audio signal by more than a threshold amount, the Nyquist frequency of said frame of the digital audio signal is lowered from its original value to a reduced value by removing spectral bands of said frame of the digital audio signal above the identified upper limit of the frequency range. Thereafter said frame of the digital audio signal is transformed from the first frequency domain to the second frequency domain via an intermediate time domain.
    Type: Grant
    Filed: June 20, 2017
    Date of Patent: September 8, 2020
    Assignee: Dolby International AB
    Inventors: Per Ekstrand, Robin Thesing, Lars Villemoes
  • Patent number: 10770079
    Abstract: An apparatus for processing an input audio signal relies on a cascade of filterbanks, the cascade having a synthesis filterbank for synthesizing an audio intermediate signal from the input audio signal, the input audio signal being represented by a plurality of first subband signals generated by an analysis filterbank, wherein a number of filterbank channels of the synthesis filterbank is smaller than a number of channels of the analysis filterbank. The apparatus furthermore has a further analysis filterbank for generating a plurality of second subband signals from the audio intermediate signal, wherein the further analysis filterbank has a number of channels being different from the number of channels of the synthesis filterbank, so that a sampling rate of a subband signal of the plurality of second subband signals is different from a sampling rate of a first subband signal of the plurality of first subband signals.
    Type: Grant
    Filed: June 22, 2018
    Date of Patent: September 8, 2020
    Assignees: Franhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V., Dolby International AB
    Inventors: Lars Villemoes, Per Ekstrand, Sascha Disch, Frederik Nagel, Stephan Wilde
  • Publication number: 20200279571
    Abstract: An apparatus for processing an input audio signal relies on a cascade of filterbanks, the cascade having a synthesis filterbank for synthesizing an audio intermediate signal from the input audio signal, the input audio signal being represented by a plurality of first subband signals generated by an analysis filterbank, wherein a number of filterbank channels of the synthesis filterbank is smaller than a number of channels of the analysis filterbank. The apparatus furthermore has a further analysis filterbank for generating a plurality of second subband signals from the audio intermediate signal, wherein the further analysis filterbank has a number of channels being different from the number of channels of the synthesis filterbank, so that a sampling rate of a subband signal of the plurality of second subband signals is different from a sampling rate of a first subband signal of the plurality of first subband signals.
    Type: Application
    Filed: May 19, 2020
    Publication date: September 3, 2020
    Inventors: Lars VILLEMOES, Per EKSTRAND, Sascha DISCH, Frederik NAGEL, Stephan WILDE
  • Publication number: 20200273476
    Abstract: The present invention relates to audio coding systems which make use of a harmonic transposition method for high frequency reconstruction (HFR). A system and a method for generating a high frequency component of a signal from a low frequency component of the signal is described. The system comprises an analysis filter bank providing a plurality of analysis subband signals of the low frequency component of the signal. It also comprises a non-linear processing unit to generate a synthesis subband signal with a synthesis frequency by modifying the phase of a first and a second of the plurality of analysis subband signals and by combining the phase-modified analysis subband signals. Finally, it comprises a synthesis filter bank for generating the high frequency component of the signal from the synthesis subband signal.
    Type: Application
    Filed: March 5, 2020
    Publication date: August 27, 2020
    Applicant: Dolby International AB
    Inventors: Lars VILLEMOES, Per HEDELIN
  • Publication number: 20200270696
    Abstract: The present invention relates to coding of audio signals, and in particular to high frequency reconstruction methods including a frequency domain harmonic transposer. A system and method for generating a high frequency component of a signal from a low frequency component of the signal is described.
    Type: Application
    Filed: March 5, 2020
    Publication date: August 27, 2020
    Applicant: Dolby International AB
    Inventors: Lars VILLEMOES, Per EKSTRAND